The present invention concerns a procedure for conducting, into a rock cistern, gas or liquid which is colder than the rock cistern temperature, wherein the gas or liquid is conducted through a feeder pipe into the rock cistern or into a gas space thereof.
The present invention also concerns a feeder pipe construction in a rock cistern for conducting gas or liquid into the rock cistern or into the gas space of the rock cistern.
Gases or liquids are stored in rock cisterns which have a space for liquid over a water bed or a dry bottom, and a gas space over the liquid space. For example, butane, propane, gas condensate, etc. may be noted among liquefied gases which may be stored in rock cisterns. Similarly, fuels such as petrol, aviation kerosene, etc., are stored in rock cisterns.
In rock cisterns without lining, where the storage temperature of the stored liquid or gas is over 0.degree. C., the ground water in the rock or an artificial curtain serves to seal the rock cistern. If cold gas or liquid (under 0.degree. C.) is conducted into the rock cistern, then the cold operating pipe will bind or sap heat from the surroundings. This causes freezing of the rock or of the surroundings of the pipe. The ground water or water curtain system in the rock or in the soil around the pipe will then freeze. Ice is produced as such, which will break structures and cause cracks in the rock and around the pipe. As a result of this damage, leaks appear in the pressurized cistern. Furthermore, freezing causes disturbances in the ground water flow or in the artificial water curtain system.